Portable engine for tools.



No. 644,753. Patented Mar. 6, I900. J. F. ALLEN. I

PORTABLE-ENGINE FOR TOOLS.

(Applicatiqn filed May 17, 1898.)

3 Sheets-Sheet I (No mum.)

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0.. wAsnmaton n c No. 644,753. Patented Mar. 6,1900.

' J. F. ALLEN.

PORTABLE ENGINE FOR TOOLS.

(Application filed May 1'7, 1898.\

3 Sheets-Sheet 2 (No Model.)

WITNESSES:

No. 644,753, Patented Mar 6, I900.

' J. F. ALLEN.

PORTABLE ENGINE FOB TOOLS.

(Application filed. May 17, 1898.)

(No Model.) 3 Sheets-Sheet 3,

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QJI. J/ J yaw UNirnn STAT S JOHN F. ALLEN, on NEW YORK, N. Y.

PORTABLE ENGINE FOR TOOLS.

SPECIFICATION forming part of Letters Patent No. 644,753, dated March 6, 1906. Application filed May 1'7 1898. Serial No. 680,928. (No model.)

To CLZZ whom it may concern:

Be it known that I, JOHN F. ALLEN, acitizen of the United States, and a resident of the city of New York, borough of Bronx, in the State of New York, have invented certain new and useful Improvements in Portable Engines for Tools, of which thefollowing is a specification, reference being had to the accompanying drawings, "forming part hereof.

This invention relates to portable tools, and has for its object generally to improve and simplify the construction of such apparatus.

According to my invention a shaft, which may be the tool-carrying shaft, is directly actuated by fluid-actuated pistons, the desired reduction of speed being effected at the connection of the pistons and shaft. A valve mechanism embodying my invention for the fluid-actuated pistons is exceedingly simple, the valve-passages being formed in the pistons. themselves and cooperating with induction and eduction ports formed in the casing to lead in and exhaust the impelling fluid which actuates the pistons.

My invention also includes Various improvements in construction, all of which will now be particularly described with reference to the accompanying drawings.

Figure 1 is a vertical central section of a portable drill embodying my invention. Fig. 2 is a horizontal section of the same on a plane passing medially through the piston-chamber and pistons, as indicated by the line 2 2, Fig. 1. Fig. 3 is a horizontal section of the same on the plane of the bottom of the lower piston-chamber, as indicated by the line 3 3, Fig. 1. Fig. 4 is a vertical section of the same on planes indicated by the line 4 4, Fig. 2. Fig. 5 is a side elevation, partly in section, of a modified construction and shows the drill in position for drilling through a flanged plate or beam.

I will first describe the construction shown in Figs. 1 to 4, inclusive. The portable drill is here shown as having an upwardly-extending centering-point 5 and is adapted to be held to its work by a brace or old man in the well known manner, the centering-point being adapted to enter a corresponding depression in the brace, while the drill 1 will be started in a centered depression punched in the work to be drilled. The drill-head 6 is shown as nal alinelnent. I tating the feed-sIeeVe-Q, which is shown as parativel-y short feed-sleeve.

formed at the lower end of the driving and tool-carrying shaft 7, and the drill is shown as'entering a socket therein and clamped by a set-screw 8. The drill 1, the driving shaft 7, and the centering-point 5 are-in longitudi= The drill is fed forward by roprovided with a hand-wheel 10 for conven ience of manipulation, and a double screwfeedis provided, which I will now describe.

The feed-sleeve 9 has an internal screwthread, which may be a left-hand thread and which engages with a corresponding external thread on the cylindrical upward projection or stud'15 of the upper head 14 of the frame or casing. The centering-point is at the upper end of' a pin 11, having a screw-thread thereon, which may be and is shown as a righthand thread,this threaded centering-pin passing through a nut 12, held in the feed-sleeve 9 or which may be a part of the sleeve 9. This centering-pin 11 has a feather or spline 13, which works in a corresponding vertical slot in the stud 15, so that the centering-pin 11 is held from rotation relatively to the cars ing, but is free to move longitudinally relatively thereto. The screw-threads upon the stud 1.5 and centering-pin 11 are in opposite directions, so that as the feed-sleeve 9 is screwed upwardly relatively to the frame the centering-pin 11 is screwed upwardly rela-' tively to the feed-sleeve, and the total feed is the sum of these two movements, and thus a large movement of the centering-pin relatively to the frame may be had with a com- It is to be observed that while the relative movements are as above described, inasmuch as the centering-pin is usually held stationary, the actual movement is produced by the feeding mechanism is usually a downward or forward movement of the frame and tool carried thereby.

The driving or tool-carryin g shaft 7 is shown as bearing at its upper end against a thrustblock 16, which may be of phosphor-bronze. Bearing-sleeves 17 are shown between the driving-shaft and the frame or casing to reduce the friction, and the bearings of the driving-shaft are in the upper head 14 and the lower head 2a of the casing or frame, and the driving-shaft is shown as held in the casing or frame by a removable pin 18, engaging an annular groove in the driving-shaft. Means are shown for oiling these parts, comprising an oil-hole formed through the nut 12 of the feed-sleeve 9, which oil-hole when registered with the spline-slot, as shown in Fig. 1, provides an oil-channel to the thrust-block 10, and the thrust-block 16 has a central oilhole therein.

Motion is communicated to the drivingshaft 7 through the spur-gear 19, which may be keyed, as shown, or otherwise held upon the driving-shaft '7, and the reciprocating pistons engage directly with this gear, and the reduction of speed usually required in constructions of this character is effected by the direct action of the movable pistons upon the gear of the driving-shaft.

The movable pistons are arranged in two sets moving in opposite directions, so that their momentum is balanced, as is usually desirable in constructions of this character; but should this balancing not be required in any instance a single set of pistons would be employed. Each set comprises two pistons the inner piston 20 and the outer piston 2l and separate piston-chambers are provided for each set of pistons, the walls of the chamber for the upper pistons being formed by the upper head 14 and the middle piece 29 of the casing and for the lower pistons by the middle piece 29 and the lower head 2-1 of the easing. Each inner piston 20 is arranged to reciprocate within its outer piston 21, and each outer piston 21 is arranged to reciprocate and carry with it the inner piston within the chambers in the casing. As shown, each inner piston 20 is of the same length as the opening in its outer piston 21, so as to have no longitudinal movement relatively thereto, but is narrower than such opening, so that it may reciprocate laterally relatively to the outer piston, and each outer piston 21 is of the same width as the chamber in the casing within which it is located, but of shorter length than such chamber, so that it may reciprocate longitudinally relatively thereto. As each outer piston reciproeates longitudinally it carries its inner piston with it, and the movement of each inner piston relatively to the casing is the resultant of its movement and that of its outer piston, and as the two pistons of each set are actuated so that one is at half-stroke when the other is at full stroke and the strokes of the pistons are all of the same length each inner piston will occupy at the end of the quarters of its full movement the dividingpoints of quarters of a circle and its path from one quarter to the next would depend upon the control exerted upon the pistons by the power-receiving device. According to my invention the inner pistons have internal gears formed therein which as the pistons are actuated move around in contact with the gear 19, the inner pistons moving in substantiallyeircular paths. Each internal gear has a greater number of teeth than the gear 19, and the forward movement imparted to the gear in each full stroke of an inner piston is a number of teeth of the gear'19 corresponding to the excess in number of teeth of the internal gear-as, for example, in the construction shown the driving-gear 19 has four teeth and the internal gear five teeth, and the gear 19 is moved forward one tooth thereof at each full stroke of an inner piston. In Fig. 2 the lower inner piston is shown at the forward end of its stroke. At the end of the next full stroke the position of the parts would be the same, except that the gear 19 would have moved forward one tooth. Hence each full stroke of the pistons rotates the driving-shaft through one-fourth of a revolution, and the reduction of speed effected at the direct connection of the pistons and driving-shaft is in the ratio of four to one. It is of course evident that by varying the numbers of teeth on the inner pistons and gear a greater or less reduction of speed may be obtained. It will also be observed that there is no dead-center in these movements and that the drill will start in any position. With the two sets of balanced pistons as shown it is usually desirable, as in the construction shown, that the gear 19 should have an even number of teeth or be of symmetrical form, with diametrically-opposite parts of the same shape, as by reason thereof the two inner pistons may be, as in the construction shown, of exactly the same shape; but if only one set of pistons were employed this reason for employing an even number of teeth on the gear 19 would not exist.

Each inner piston 20 forms the valve for the induction and eduction of the compressed air or other impelling fluid. Four valve-passages 22 are provided in each inner piston, one for each side of each piston, these valvepassages extending upward vertically from the lower face of the lower inner piston 20 and downward vertically from the upper face of the upper inner piston 20 to about the middle of the height of the pistons and then extending at right angles horizontally and opening into the chambers to which they are to lead in and from which they are to lead out the impelling fluid. The valve-passages 22 for the inner pistons open directly into their proper chambers, while those for the outer pistons are connected with their proper chambers by passages 01' slots 23 in the outer pistons, these slots being of sufficient length to accommodate the movements of the inner pistons.

The ports for the lower pistons are formed in the upper face of the lower head 24 of the casing and those for the upper pistons are formed in the lower face of the upper head 14 of the casing. The ports and passages for the lower pistons are particularly shown in Fig. 3. The induction-ports 25 extend from the induction-passages 26 in the heads of the casing, and the exhaust or eduction ports 27 open into the eduction-passages 28 in the heads of the casing. Four induction-ports 25 and four eduction-ports 27 are shown as provided for each set of pistons. The paths of the inner pistons being substantially circular, the ports are arranged in pairs in circles representing the paths of the val ve-ports 22 in the movements of the inner pistons. For example, the dotted circle a: in Fig. 3 represents the path of the center of the valve port at the rear left-hand side of the lower inner piston, and, as shown in Fig. 2, the lower inner piston 20 is at the forward end of its stroke and the induction-port 25 is closed and the eduction-port 27 slightly open, the arrangement shown providing the usual slight lead in the opening of the ports. So also the lower outer piston 21 being shown at the middle of its movement toward the right, the left-hand induction-port 25 is nearly wide open and the right-hand educt-ion-port 27 is nearly wide open, the slight variation from wide-open position resulting from the lead. The direction of movement of the inner pistons would be the reverse of the hands of a clock, while the direction of rotation of the gear and driving-shaft would be the same as the hands of a clock, as indicated in Fig. 3.

As shown, the compressed air or other impelling fluid enters the casing at the left-hand end of the casing and is exhausted at the right-hand end of the casing, and at each end of the casing a hole is tapped, designed to form a socket for a tube or hollow handle and entering a cross-passage in the middle piece 29 of the casing. The cross-passages at the left-hand end are parts of the induction-pas sages 26, as clearly shown in Fig. 4:, and correspondingly the cross-passages at the righthand end are parts of the eduction-passages 28. Hollow handles 31 and 34 are shown in Fig. 5 screwed into the sockets at the ends of the casing, the handle 31 at the induction end having a throttle-cock 32 therein to control the supply of compressed air or other impelling fluid and start and stop the drill, and an oil-cup 33 is tapped into the middle piece 29 of the casing to supply oilor other lubricant to the induction-passages, so that the oil will be carried by the compressed air through all working parts.

The construction above described may be modifiedin manyparticulars within the scope of my inventionas, for example, as shown in Fig. 5, the driving-shaft 7 and drill 1 may be fed forward relatively to the casing and other parts. This modified construction is particularly adapted for drilling holes in flanged plates or beams, and an arched brace 35 is provided which is fixed to the casing and adapted at its outer end to bear against the back of the flange to be drilled. The driving-shaft 7 is connected to the driving-gear 19, as by splines and slots, so as to be rotated by the driving-gear, but to be movable longitudinally relatively thereto, and a feed-screw 36, which, as shown, has a crank and handle 37 thereon, is tapped into the stud 15 of the casing and bears against the rear end of the driving-shaft 7.

I have shown my invention as applied to a portable drilling-machine; but it is of course evident that my invention or parts thereof may be embodied in other forms of portable tools or power-operated tools or other apparatus or machines.

Various modifications other than the modification above described may be made in the construction, and parts of my invention may be used separately or combined with other parts of different construction from those,

. each full stroke of 7 the pistons causes a rotation of the driving-shaft through a part only of a revolution, substantially as set forth.

2. The combination with a driving-shaft of two pistons arranged to move in different directions, one of said pistons being carried by the other piston and having a speed-reducing connection directly to said driving-shaft, substantially as set forth.

3. The combination with a driving-shaft having a gear-wheel thereon, of a piston hav-' ing an internal gear thereon meshing with the gear-wheel of the drivin g-shaft and means for actuating the piston to move the internal gear eccentrically relatively to the gear-wheel.

4. The combination with a driving-shaft having a gear-wheel thereon, of two pistons arranged to move in different directions and a casing for said pistons, one of said pistons being carried by the other piston and having an internal gear thereon meshing with said gear-wheel.

5. The combination with a driving-shaft having a gear-wheel thereon, of an inner piston and an outer piston and a casing therefor, the inner piston being carried by the outer piston and having an internal gear thereon meshing with said gear-wheel and said internal gear and gear-wheel having different numbers of teeth, and the inner piston having valve-passages therein and the casing having ports therein arranged to 006perate with such valve-passages, substantially as set forth.

6. A power-operated tool provided with a driving-shaft having a gear-wheel thereon, an inner and outer piston and a casing therefor, the inner piston being carried by the outer piston and the two pistons being arranged to move substantially at right angles to each other and the inner piston having an internal gear thereon meshing with said gearwheel and said internal gear and gear-Wheel having different numbers of teeth, and the inner piston' having valve-passages therein and the casing having ports therein arranged to cooperate with such valve-passages, substantially as set forth.

7. The combination of an inner and outer fluid-actuated piston and a casing therefor, the inner piston being carried by the outer piston and movable in one direction relatively thereto and the outer piston being movable in a difierent direction relatively to the easing, and the inner piston having valve-passages with ports opening against the casing, for the eduetion and induction of fluid to actuate the inner piston and other valve-passages therein for the eduction and induction of fluid to operate the outer piston, and the casing having induction and eduction ports arranged successively in the paths of said piston-valve ports and the outer piston having passages arranged to cooperate with those valve-passages of the inner piston for the eduction and induction of fluid to actuate the outer piston, substantially as set forth.

8. A power-operated tool provided with a driving-shaft having a gear-wheel thereon, an inner and outer piston and a casing therefor, the inner piston being carried by the outer piston and movable in one direction relatively thereto and the outer piston being movable in a different direction relatively to the easing, and the inner piston having an internal gear thereon meshing with said gear vheel and said internal gear and gear-wheel having different numbers of teeth, and the inner piston having valve-passages therein and the casing having induction and eduction ports therein arranged to cooperate with such valve-passages and the outer piston having passages arranged to cooperate with those valve-passages of the inner piston for the induction and eduction of fluid to actuate the outer piston, substantially as set forth.

9. The combination with a driving-shaft having a gear-wheel thereon, said gear-wheel having an even number of teeth, of two sets of inner and outer fluid-actuated pistons oppositely arranged whereby their momentums are balanced, each inner piston being carried by its outer piston and movable in one direction relatively thereto and each outer piston being movable relatively to the casing in a direction substantially at right angles to the direction of movement of its inner piston relatively to it, and each inner piston having an internal gear thereon meshing with said gear-wheel and said internal gear and gearwheel having different numbers of teeth, substantially as set forth.

10. A power-operated tool provided with the toolcarrying shaft 7 having the gearwheel 19 thereon, a casing comprising the middle piece 29 and the heads 14 and 24, the two sets of inner pistons 20 and outer pistons 21, each inner piston being carried by its outer piston and movable in one direction relatively thereto and each outerpiston being movable relatively to the casing in a direction substantially at right angles to the direction of movement of its inner piston relatively to it, and each inner piston having an internal gear thereon meshing with said gear-wheel 19 and having a number of teeth diiferent from that of said gear-wheel, and each inner piston having valve-passages 22 therein and the easing-heads 14 and 24 having induction-ports 25 and eduetion-ports 27 therein arranged to cooperate with said valve-passages, and each outer piston having passages 23 therein arranged to cooperate with those valve-passages 22 of the inner piston for the induction and eduction of fluid to actuate the outer piston, and the casing-heads 14 and 24 having eduction and induction passages 26 and 28 therein, substantially as set forth.

Signed at the city of New York, State of New York, this 14th day of May, A. D. 1898.

JOHN F. ALLEN. Witnesses:

HENRY D. WILLIAMS, HERBERT II. GIBBS. 

